java - 如何使用 setAutoCreateColumnsFromModel(false) 从 TableModel 和 TableColumnModel 中删除 JTable 列？

标签 java swing jtable

最后查看我的 SSCCE 代码。我想要实现的是:

  • 数据模型和列模型中的列数相同
  • 使用 setAutoCreateColumnsFromModel(false) 避免在数据/表模型添加或删除列时重新创建列模型
  • 能够移动列

大按钮在末尾添加了一个新列。每个新列都有一个唯一标识符。

enter image description here

标题有一个右键单击菜单 HeaderMenu 以删除列。计时器调用 table.tableModel.addRow() 以在顶部插入新行。每列的数据由 Column 类生成。在此演示中，该值只是一个带有列标识符的行计数器。

enter image description here

在实际表中(不是这个演示)

  • 每一列都是Column的子类并生成有意义的数据
  • 菜单还包含向左/向右插入和替换。这是通过使用类似于演示添加/删除方法并将列移动到所需位置来实现的
  • 数据模型可能包含十几个列和超过一百万行
  • 可以添加几毫秒到几秒之间的时间间隔的行，即性能很重要

此演示演示了删除列会产生如下错误的问题:

Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 2 >= 2
at java.util.Vector.elementAt(Vector.java:477)
at javax.swing.table.DefaultTableModel.getValueAt(DefaultTableModel.java:649)
at javax.swing.JTable.getValueAt(JTable.java:2720)
at javax.swing.JTable.prepareRenderer(JTable.java:5712)
at javax.swing.plaf.basic.BasicTableUI.paintCell(BasicTableUI.java:2114)
...

请指教如何修复它。这是完整的代码:

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;
import java.util.Vector;

import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JPopupMenu;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableColumn;

@SuppressWarnings("serial")
public class TableDemo extends JTable {

    private static class Column {

        private int rowsCounter = 0;
        private final String identifier;

        public Column(String identifier) {
            this.identifier = identifier;
        }

        private String nextCellValue() {
            return (rowsCounter++) + ", id: " + identifier;
        }
    }

    private static class MyTableModel extends DefaultTableModel {

        private final List<Column> columns = new ArrayList<>();
        private int nextColumnIdentifier = 0;

        private void addRow() {
            Object[] row = columns.stream().map(Column::nextCellValue).toArray();
            insertRow(0, row);
        }

        private TableColumn addColumn() {
            String identifier = String.valueOf(nextColumnIdentifier++);
            columns.add(new Column(identifier));
            addColumn(identifier);
            TableColumn tc = new TableColumn();
            tc.setIdentifier(identifier);
            tc.setHeaderValue(identifier);
            tc.setModelIndex(columns.size() - 1);
            return tc;
        }

        private void removeColumn(int idx) {
            columns.remove(idx);
            columnIdentifiers.remove(idx);
            for (Object row : dataVector) {
                ((Vector<?>) row).remove(idx);
            }
            fireTableStructureChanged();
        }
    }

    private static class HeaderMenu extends JPopupMenu {

        private int columnViewIndex;

        private HeaderMenu(final TableDemo table) {
            JMenuItem item = new JMenuItem("Delete column");
            item.addActionListener(e -> table.deleteColumn(columnViewIndex));
            add(item);

            final MouseAdapter ma = new MouseAdapter() {

                boolean dragged = false;

                @Override
                public void mouseReleased(MouseEvent e) {
                    if (!dragged && e.getButton() == MouseEvent.BUTTON3) {
                        final Point p = e.getPoint();
                        SwingUtilities.invokeLater(() -> {
                            columnViewIndex = table.columnAtPoint(p);
                            show(e.getComponent(), p.x, p.y);
                        });
                    }
                    dragged = false;
                }

                @Override
                public void mouseDragged(MouseEvent e) {
                    dragged = true;
                }
            };

            table.getTableHeader().addMouseListener(ma);
            table.getTableHeader().addMouseMotionListener(ma);
        }
    }

    private MyTableModel tableModel = new MyTableModel();

    private TableDemo() {
        new HeaderMenu(this);
        setModel(tableModel);
        setAutoCreateColumnsFromModel(false);
        setDefaultEditor(Object.class, null);
    }

    private void addColumn() {
        TableColumn tc = tableModel.addColumn();
        addColumn(tc);
    }

    void deleteColumn(int idxView) {
        TableColumn tc = getColumnModel().getColumn(idxView);
        tableModel.removeColumn(tc.getModelIndex());
        removeColumn(tc);
    }

    private static void buildAndShowGui() {
        TableDemo table = new TableDemo();
        table.setPreferredScrollableViewportSize(new Dimension(800, 300));
        table.setFillsViewportHeight(true);
        JScrollPane tableScrollPane = new JScrollPane(table);
        JButton buttonAdd = new JButton("Add column");
        buttonAdd.addActionListener(e -> table.addColumn());
        int gaps = 10;
        JPanel panel = new JPanel(new BorderLayout(gaps, gaps));
        panel.setBorder(BorderFactory.createEmptyBorder(gaps, gaps, gaps, gaps));
        panel.add(buttonAdd, BorderLayout.NORTH);
        panel.add(tableScrollPane, BorderLayout.CENTER);
        JFrame frame = new JFrame(table.getClass().getSimpleName());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setContentPane(panel);
        frame.pack();
        frame.setVisible(true);

        new Timer().schedule(new TimerTask() {

            @Override
            public void run() {
                SwingUtilities.invokeLater(() -> table.tableModel.addRow());
            }
        }, 500, 100);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> buildAndShowGui());
    }
}

最佳答案

问题是，从表/数据模型中的某些 modelIndex 中删除列后，TableColumn#getModelIndex()列模型中的某些列可能会移动 1。这是一个示例，假设该表有 3 列并且下面的代码生成 0 1 2:

for (int i = 0; i < getColumnModel().getColumnCount(); i++) {
    System.out.print(getColumnModel().getColumn(i).getModelIndex() + " ");
}

然后从数据模型和列模型中删除列 1 后，此代码的输出变为:0 2。因此，当访问数据模型中不存在的列 2 时，JTable 会产生 ArrayIndexOutOfBoundsException。这就是删除最后一列不会产生错误的原因。

解决方案是移动已删除列右侧列的modelIndex。这可以通过自定义 TableColumnModel 来完成:

private static class MyColumnsModel extends DefaultTableColumnModel {

    private TableColumn deleteColumn(int idxView) {
        if (selectionModel != null) {
            selectionModel.removeIndexInterval(idxView, idxView);
        }
        TableColumn tc = tableColumns.remove(idxView);
        tc.removePropertyChangeListener(this);
        for (TableColumn tableColumn : tableColumns) {
            if (tableColumn.getModelIndex() > tc.getModelIndex()) {
                tableColumn.setModelIndex(tableColumn.getModelIndex() - 1);
            }
        }
        return tc;
    }
}

以及表的添加/删除方法如下:

private void addColumn() {
    TableColumn tc = tableModel.addColumn();
    addColumn(tc); // equal to columnsModel.addColumn(tc);
}

private void deleteColumn(int idxView) {
    TableColumn tc = columnsModel.deleteColumn(idxView);
    tableModel.removeColumn(tc.getModelIndex());
}

这是完整的固定代码:

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;
import java.util.Vector;

import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JPopupMenu;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.table.DefaultTableColumnModel;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableColumn;

@SuppressWarnings("serial")
public class TableDemo extends JTable {

    private static class Column {

        private int rowsCounter = 0;
        private final String identifier;

        public Column(String identifier) {
            this.identifier = identifier;
        }

        private String nextCellValue() {
            return (rowsCounter++) + ", id: " + identifier;
        }
    }

    private static class MyTableModel extends DefaultTableModel {

        private final List<Column> columns = new ArrayList<>();
        private int nextColumnIdentifier = 0;

        private void addRow() {
            Object[] row = columns.stream().map(Column::nextCellValue).toArray();
            insertRow(0, row);
        }

        private TableColumn addColumn() {
            String identifier = String.valueOf(nextColumnIdentifier++);
            columns.add(new Column(identifier));
            addColumn(identifier);
            TableColumn tc = new TableColumn();
            tc.setIdentifier(identifier);
            tc.setHeaderValue(identifier);
            tc.setModelIndex(columns.size() - 1);
            return tc;
        }

        private void removeColumn(int idx) {
            columns.remove(idx);
            columnIdentifiers.remove(idx);
            for (Object row : dataVector) {
                ((Vector<?>) row).remove(idx);
            }
            fireTableStructureChanged();
        }
    }

    private static class MyColumnsModel extends DefaultTableColumnModel {

        private TableColumn deleteColumn(int idxView) {
            if (selectionModel != null) {
                selectionModel.removeIndexInterval(idxView, idxView);
            }
            TableColumn tc = tableColumns.remove(idxView);
            tc.removePropertyChangeListener(this);
            for (TableColumn tableColumn : tableColumns) {
                if (tableColumn.getModelIndex() > tc.getModelIndex()) {
                    tableColumn.setModelIndex(tableColumn.getModelIndex() - 1);
                }
            }
            return tc;
        }
    }

    private static class HeaderMenu extends JPopupMenu {

        private int columnViewIndex;

        private HeaderMenu(final TableDemo table) {
            JMenuItem item = new JMenuItem("Delete column");
            item.addActionListener(e -> table.deleteColumn(columnViewIndex));
            add(item);

            final MouseAdapter ma = new MouseAdapter() {

                boolean dragged = false;

                @Override
                public void mouseReleased(MouseEvent e) {
                    if (!dragged && e.getButton() == MouseEvent.BUTTON3) {
                        final Point p = e.getPoint();
                        SwingUtilities.invokeLater(() -> {
                            columnViewIndex = table.columnAtPoint(p);
                            show(e.getComponent(), p.x, p.y);
                        });
                    }
                    dragged = false;
                }

                @Override
                public void mouseDragged(MouseEvent e) {
                    dragged = true;
                }
            };

            table.getTableHeader().addMouseListener(ma);
            table.getTableHeader().addMouseMotionListener(ma);
        }
    }

    private MyTableModel tableModel = new MyTableModel();
    private MyColumnsModel columnsModel = new MyColumnsModel();

    private TableDemo() {
        new HeaderMenu(this);
        setModel(tableModel);
        setColumnModel(columnsModel);
        setAutoCreateColumnsFromModel(false);
        setDefaultEditor(Object.class, null);
    }

    private void addColumn() {
        TableColumn tc = tableModel.addColumn();
        addColumn(tc); // equal to columnsModel.addColumn(tc);
    }

    private void deleteColumn(int idxView) {
        TableColumn tc = columnsModel.deleteColumn(idxView);
        tableModel.removeColumn(tc.getModelIndex());
    }

    private static void buildAndShowGui() {
        TableDemo table = new TableDemo();
        table.setPreferredScrollableViewportSize(new Dimension(800, 300));
        table.setFillsViewportHeight(true);
        JScrollPane tableScrollPane = new JScrollPane(table);
        JButton buttonAdd = new JButton("Add column");
        buttonAdd.addActionListener(e -> table.addColumn());
        int gaps = 10;
        JPanel panel = new JPanel(new BorderLayout(gaps, gaps));
        panel.setBorder(BorderFactory.createEmptyBorder(gaps, gaps, gaps, gaps));
        panel.add(buttonAdd, BorderLayout.NORTH);
        panel.add(tableScrollPane, BorderLayout.CENTER);
        JFrame frame = new JFrame(table.getClass().getSimpleName());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setContentPane(panel);
        frame.pack();
        frame.setVisible(true);

        new Timer().schedule(new TimerTask() {

            @Override
            public void run() {
                SwingUtilities.invokeLater(() -> table.tableModel.addRow());
            }
        }, 500, 100);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> buildAndShowGui());
    }
}

关于java - 如何使用 setAutoCreateColumnsFromModel(false) 从 TableModel 和 TableColumnModel 中删除 JTable 列？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/57565397/

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